[4.9-stable PATCH 10/11] mm: fail get_vaddr_frames() for filesystem-dax mappings
commit b7f0554a56f21fb3e636a627450a9add030889be upstream.
Until there is a solution to the dma-to-dax vs truncate problem it is
not safe to allow V4L2, Exynos, and other frame vector users to create
long standing / irrevocable memory registrations against filesytem-dax
vmas.
[dan.j.willi...@intel.com: add comment for vma_is_fsdax() check in
get_vaddr_frames(), per Jan]
Link:
http://lkml.kernel.org/r/151197874035.26211.4061781453123083667.st...@dwillia2-desk3.amr.corp.intel.com
Link:
http://lkml.kernel.org/r/151068939985.7446.15684639617389154187.st...@dwillia2-desk3.amr.corp.intel.com
Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Dan Williams
Reviewed-by: Jan Kara
Cc: Inki Dae
Cc: Seung-Woo Kim
Cc: Joonyoung Shim
Cc: Kyungmin Park
Cc: Mauro Carvalho Chehab
Cc: Mel Gorman
Cc: Vlastimil Babka
Cc: Christoph Hellwig
Cc: Doug Ledford
Cc: Hal Rosenstock
Cc: Jason Gunthorpe
Cc: Jeff Moyer
Cc: Ross Zwisler
Cc: Sean Hefty
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
---
mm/frame_vector.c | 12
1 file changed, 12 insertions(+)
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index db77dcb38afd..375a103d7a56 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -52,6 +52,18 @@ int get_vaddr_frames(unsigned long start, unsigned int
nr_frames,
ret = -EFAULT;
goto out;
}
+
+ /*
+* While get_vaddr_frames() could be used for transient (kernel
+* controlled lifetime) pinning of memory pages all current
+* users establish long term (userspace controlled lifetime)
+* page pinning. Treat get_vaddr_frames() like
+* get_user_pages_longterm() and disallow it for filesystem-dax
+* mappings.
+*/
+ if (vma_is_fsdax(vma))
+ return -EOPNOTSUPP;
+
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
vec->got_ref = true;
vec->is_pfns = false;
[4.9-stable PATCH 10/11] mm: fail get_vaddr_frames() for filesystem-dax mappings
commit b7f0554a56f21fb3e636a627450a9add030889be upstream.
Until there is a solution to the dma-to-dax vs truncate problem it is
not safe to allow V4L2, Exynos, and other frame vector users to create
long standing / irrevocable memory registrations against filesytem-dax
vmas.
[dan.j.willi...@intel.com: add comment for vma_is_fsdax() check in
get_vaddr_frames(), per Jan]
Link:
http://lkml.kernel.org/r/151197874035.26211.4061781453123083667.st...@dwillia2-desk3.amr.corp.intel.com
Link:
http://lkml.kernel.org/r/151068939985.7446.15684639617389154187.st...@dwillia2-desk3.amr.corp.intel.com
Fixes: 3565fce3a659 ("mm, x86: get_user_pages() for dax mappings")
Signed-off-by: Dan Williams
Reviewed-by: Jan Kara
Cc: Inki Dae
Cc: Seung-Woo Kim
Cc: Joonyoung Shim
Cc: Kyungmin Park
Cc: Mauro Carvalho Chehab
Cc: Mel Gorman
Cc: Vlastimil Babka
Cc: Christoph Hellwig
Cc: Doug Ledford
Cc: Hal Rosenstock
Cc: Jason Gunthorpe
Cc: Jeff Moyer
Cc: Ross Zwisler
Cc: Sean Hefty
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
---
mm/frame_vector.c | 12
1 file changed, 12 insertions(+)
diff --git a/mm/frame_vector.c b/mm/frame_vector.c
index db77dcb38afd..375a103d7a56 100644
--- a/mm/frame_vector.c
+++ b/mm/frame_vector.c
@@ -52,6 +52,18 @@ int get_vaddr_frames(unsigned long start, unsigned int
nr_frames,
ret = -EFAULT;
goto out;
}
+
+ /*
+* While get_vaddr_frames() could be used for transient (kernel
+* controlled lifetime) pinning of memory pages all current
+* users establish long term (userspace controlled lifetime)
+* page pinning. Treat get_vaddr_frames() like
+* get_user_pages_longterm() and disallow it for filesystem-dax
+* mappings.
+*/
+ if (vma_is_fsdax(vma))
+ return -EOPNOTSUPP;
+
if (!(vma->vm_flags & (VM_IO | VM_PFNMAP))) {
vec->got_ref = true;
vec->is_pfns = false;
